1. Technical Field
The present disclosure generally relates to drainage devices, and particularly, to a drainage device for draining liquid out of a closed chamber.
2. Description of the Related Art
In the discharge of sewage, sewage is generally sucked into a container to be purified by a water suction cleaner, and then discharged outside. The sewage suction cleaner includes a closed chamber and an air pump. The air pump creates a certain degree of vacuum in the closed chamber. Under the negative air pressure, the sewage is pushed into the closed chamber. However, when discharging the sewage, outside air will flow into the closed chamber via an outlet, and thus the degree of vacuum of the closed chamber is decreased. As a result, the air pressure difference between the inside and the outside of the closed chamber is decreased, and sewage is not forced as strongly into the closed chamber.
Therefore, there is room for improvement within the art.